tanh, tanhf, tanhl - hyperbolic tangent function
#include <math.h> double tanh(double x); float tanhf(float x); long double tanhl(long double x);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
These functions return the hyperbolic tangent of
x, which is
defined mathematically as:
tanh(x) = sinh(x) / cosh(x)
On success, these functions return the hyperbolic tangent of
x is a NaN, a NaN is returned.
x is +0 (-0), +0 (-0) is returned.
x is positive infinity (negative infinity), +1 (-1) is
No errors occur.
C99, POSIX.1-2001, POSIX.1-2008.
The variant returning
double also conforms to SVr4, 4.3BSD,
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